Electrostatically stabilized one-dimensional intercalation enables ultrapermeable and antifouling MXene membranes for dye wastewater purification

Two-dimensional MXene membranes are promising for dye wastewater purification. Herein, we propose an electrostatically stabilized one-dimensional intercalation strategy to construct ultrapermeable and antifouling MXene membranes, in which polyaniline-coated cellulose nanofibers (CNFs@PANI) are intercalated into Ti 3 C 2 T x nanosheets and deposited onto a PVDF substrate via vacuum filtration. The introduction of flexible one-dimensional intercalants effectively widens the interlayer spacing and forms a loose yet stable transport architecture, while the electrostatic interactions induced by PANI coating ensure robust interlayer stabilization and suppress membrane compaction and collapse during filtration. Benefiting from the synergistic interlayer modulation, the membrane delivers an ultrahigh pure water permeability of 273.3 L m −2 h −1 bar −1 , representing a 15-fold enhancement compared with pristine Ti 3 C 2 T x membranes, while maintaining rejection ratios of 99.3% for rhodamine B and 100% for congo red. Moreover, rejection efficiencies exceeding 90% are achieved for oil-water emulsions such as n-hexane/water. Beyond microstructural regulation, the spiral flow configuration further enhances local shear stress, as validated by computational fluid dynamics simulations, effectively mitigating contaminant deposition and adhesion. Consequently, the flux recovery ratio of the intercalated MXene membrane reaches 96.9%, significantly outperforming the pristine counterpart. Finally, the durability and practical wastewater treatment capacity of this membrane have also been verified, and it possesses potential for large-scale production.